FLIGHT JULY 8TH, 1948
degree to which John Stringfellow was able to look into
the future. Nearly all the essential features of modern
aircraft .were incorporated in his model, even if they
were still in a somewhat crude form. A study of bird
flight led him to believe that there were great virtues
in the flexible, single-surface trailing-edge. • Many of
the early full-size machines had this characteristic wing
construction, the theory being that it adapted itself to
the air currents. It has now been abandoned, but we-
are back again to something of the sort in the hunt for
some device which will relieve the stresses in the wings
of an aircraft when it meets a sharp-edged gust. In
the Brabazon Mr. Russell uses deflecting flaps to achieve
the same thing as did the flexible trailing-edge, so per-
haps the pioneers were not so far wrong after all.
The Wright brothers made a different approach to
the problem by building a wind tunnel for their model
tests, but the free-flying model has come into use again
in the most recent times for exploring flight at super-
sonic speeds. We have the advantage that we can
govern the flight of a model by remote control (not
too consistently, so far), but a hundred years ago the
limited Stringfellow success was at least as great a
triumph. He proved that a fixed-wing machine could
be sustained in the air by the lift of its wings, generated
by its forward speed. And this was at a time when most
experimenters were trying to emulate the birds with their
flapping wings, a task which modern high-speed photo-
graphy has shown to be quite beyond mechanical
solution.
The Northolt DisasterV
ERTICAL '' stacking '' has been criticised from
many sides and on various grounds, not the least
being the danger of icing to the aircraft which are
unfortunate enough to be given the layer in which icing
conditions may obtain. The system was given another
blow by the disaster which befell the Scandinavian DC-6
and the R.A.F. York near Northolt last Sunday.
The collision brought home the fact that the system
contains other risks. In this case there was no question
of icing. The York had arrived from Malta and had
been circling for about an hour. The DC-6 had come
from Scandinavia, and the pilot advised Control that
he proposed returning to Amsterdam.
Ministry regulations covering standard instrument-
approach and holding procedures were issued as Notice
CONTENTS
Outlook
Vampire Venturers
Hamble Heyday -
Here and There ------
Civil Aviation News
International Gliding Contests
Auster Trainer -----
Eglinton Excitement -
Balliol at Bitteswell
Leadership in the R..A.F. ....
Commonwealth Research -
Correspondence
Service Aviation
Forthcoming Events, page 53
29
31
33
35
37
41
46
48
50
51
52
53
54
to Airmen No. 117 of 1948, and lays down the proper
procedure to be followed. In this particular instance
there were only four aircraft " stacked " over the airpoft,
so it cannot be argued that the accident was due to over-
crowding. The DC-6, it appears, was at the lowest
height (2,500ft), with the York next above it at 3,000ft
and the other two aircraft above them.
From what took place it would seem that some error
either by Approach Control or in pilot's procedure must
have been responsible for the accident. When an air-
craft wishes to leave the "stack,"' the pilot must obtain
permission from Approach Control, who, in turn, obtain
the height, the route, and the "gate" from which the.
aircraft must leave the Metropolitan Control Zone from
Uxbridge Control. Approach Control passes this in-
formation to the aircraft. If both aircraft set their alti-
meters correctly after obtaining QFE from Approach
Control they should have been separated vertically by
500ft, and if both had obeyed instructions that permis-
sion must be obtained to leave the " stack," they would
have remained separated vertically until Uxbridge knew
it was safe to climb or to lose height. Thus one is forced
to the conclusion that the accident must have been
caused by a flaw in the system of vertical "stacking."
Doubtless the report of the Inspector of Accidents will
ascertain the exact cause and allocate the blame.
What is sorely needed is a unification of navigational
aids to ensure precision flying in small areas, or the
alternative of having each aircraft fitted with an orbit-
meter, as is done in the R.A.F. ^Transport Command.
"Flight" photograph.
TRANSPORT COLUMN, 1948 : Travellers last week on the railway which skirts the Handiey Page airfield at RqdietPSmwsjthis parqcj
of a score or so of Hastings C. Mk. I high-speed military transports (Bristol Hercules engines). Having regard to the newsfrbUrSerlin
it is good to know that the R.A.F. has already taken delivery of more than this number of Hastings. The nearest machine, incidentally,
has the new Transport Command lacquer finish.